1. Field of the Invention
The present invention relates to a photo sensor and a flat panel display using the same.
2. Discussion of Related Art
In recent years a variety of flat panel display devices having reduced weight and volume in comparison to a cathode ray tube (CRT) have been developed. The flat panel display devices include a liquid crystal display (LCD), a field emission display (FED), a plasma display panel (PDP), an organic light emitting display (OLED), etc.
Among the flat panel display devices, the organic light emitting display displays an image using organic light emitting diodes (OLEDs) that emit light through recombination of electrons and holes.
The organic light emitting display has been increasingly used in the field of applications such as PDA, MP3 players in addition to mobile phones due to its various advantages such as excellent color reproduction and slimness.
An image displayed in the flat panel display devices shows variance in visibility according to the luminance of ambient light. In other words, although an image is displayed with the same luminance, the displayed image appears relatively dark when ambient light has high luminance, and the displayed image appears relatively bright when the ambient light has low luminance.
Thus, to improve visibility by sensing the luminance of ambient light, the luminance of the displayed image increased when the ambient light has high luminance and the luminance of the displayed image is decreased when the ambient light has low luminance. Also, when the luminance of the displayed image is controlled according to the luminance of the ambient light, there is no need to unnecessarily increase the luminance of the displayed image, such that it is possible to reduce power consumption.
Therefore, a method for controlling luminance of a displayed image in accordance with luminance of the ambient light, using a photo sensor for sensing the ambient light attached to a flat panel display device, has been developed.
However, the use of the photo sensor is difficult due to its low power output when the photo sensor is installed inside a panel of the flat panel display device.